Pulverizing apparatus.



L%QL1%% CRITES.

PULVERIZING APPARATUS.

APPLICATION FILED JULY 3.19m

Patented Apr. 3, 1912.

2 SHEETS-SHEET l- J. CRITES.

PULVERIZING APPARATUS.

APPLICATION FILED JULY 3.19MB.

Patented Apr. 3, 1917.

2 SHEETS-SHEET 2.

STATES hart;

orric a 30E CRITES, OF CHICAGO, ILLINOIS, ASSIGNOR TO RAYMOND BROTHERS IMPACT JPULVERIZER COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

. PULVERIZING APPARATUS.

1,221,1l t4l.

To all whom/ it may concern:

Be it known that 1, JOE CRrrEs, a citizen I of the United. States, residing at Chicago,

in the county of Cook and State of Illinois, have-invented certain new and useful Improvements in Pulverizing Apparatus, of which the following is a specification.

My invention relates to pulverizing apparatus of the centrifugal impact type, and

' materials.

The invention consists in the novel arrangements, constructions and devices, to be hereinafter described and claimed, for carrying out the above stated object and such other incidental objects as will appear from bit a discharge opening 15.

the following description.

The invention is illustrated in the accompanying drawings in certain preferred embodiments wherein Figure 1 is a fra mentary elevation, with parts in section, 0 a pulverizing mill embodying one form of the invention.

' Fig. 2 is a side view, on an enlarged scale, of the pulverizing element of the mill. Fig. 3 is an edge view'of the same.

Fig. 4 is a fragmentary sectional view, illustrating a modified arrangement, and

Fig. 5 is a similar view showing the same construction but with the impact pulverizing element adjusted to-a difi'erent position Like charactersof reference designate like parts in'the several figures of the drawings. Referring first to Figs. 1 to 3 inclusive, 1O designates the pulverizing chamber formed in one end with a feed opening 11 communicating with the feed hopper 12. The other end of the pulverizing chamber is formed with a discharge opening 13 communicating with a fan chamber 14having ['he pulverizing element and the fan are preferably arranged on a single shaft 16 extending through the hopper, pulverizing chamber and fan chamber. The shaft is shown as driven by belt 17 The pulverizing element consists of a disk 18 formed with a hub'19 and provided at its periphery with a plurality of heaters 20.

Specification of Letters Patent.

Application filed July 3, 1916. 'SerialNo.107,318.

Patented Apr. 3, 191?.

The fan consists of a plurality of fan blades 21 secured to the spokes 22 of a revoluble member 23 fixed to shaft 16.

The impact pulverizing element is secured to the shaft 16 so that it may be convenientl adjusted on the shaft longitudinally thereo Two diametrical slots 24:, 25 are cut through the disk, the former extending from the periphery of the disk to the central opening in the hub. The slot 25 terminates short of the periphery of the disk and is connected with the central opening in the hub by a thin out 26. 27 isa clamping screw in the hub 19 eX- tending across the slot 24, the hub being cut away at 28 to form'a recess for the head 29 of the screw. The hub has an interior longitudinal groove into which projects a key 30 fixed to the shaft 16.

- The pulverizing chamber is bounded by a conical surface 31 which flares in the direction of the fan chamber and by an oppositely inclined conical surface 32 which tapers toward the fan chamber.

The arrangement shown in Figs: 4 and 5. is substantially the same as that just described except that a regulator is arranged a in the portion of the. pulverizing chamber regulator consisting of radial arms 33 attached to a hub 34 secured to shaft 16*.

Operation (Figs. 1 to 3 inclusive): The

material entering the pulverizing chamber 10 bounded by the conical surface 32 this fan chamber through opening 15. -The de- 'gree of pulverization of the material depends uponthe length of time to which it is subjected to the impacts of heaters 20, that is, the degree of fineness depends upon the rate at which the material moves through the mill, other conditions being equal. The

. force tendingto withdraw the material from the pulverizing chamber is primarily the draft createdby the fan. The pulverizing eleinent in revolving at a high speed produces a whirling movement in the air and suspended particles and thereby drives the particles by impact and centrifugal force against the bounding surface of the pulverizing chamber. The material moves in a stratum or film along the wall of the pulverizing chamber toward the discharge opening. As the longitudinal component of the force is greater in proportion to the radial the radially applied force by impact with the inclined surface is given a longitudinal component opposite to the longitudinal force exerted by the fan. The velocity of the particles is also increased due to the diminishing radius of the spiral so that, as far as particles of a certain size, or greater, are concerned, the force exerted by the fan is unable to overcome the forces opposed thereto and such larger particles are held back in the mill until they are reduced to the degree of fineness necessary for their discharge. While this retardation of the peripheral stratum occurs in cone 32, the effect, of

' course, is to slowup'the movement of the material all along the wall of cone 31 so that when the mill is in operation under normal conditions the larger particles are, in fact, held back within the influence of the beaters until they have been reduced to the required degree of fineness.

This degree of'fineness is varied by an adjustment of the impact element on shaft 16. With the impact element close to the feed opening, as shown in the full lines in Fig. 1, the spirally moving particles forming the peripheral stratum have to move an appreciable distance from the heaters before the conical surface 32 is reached. Moreover, the radius of the spiral movement is constantly increasing due to the flareof cone 31,

this cone thereby operating to increase the speed at which the. material passes therethrough just as the oppositely inclined conical surface 32 operates to retard the outward movement of the material. As a result of these conditions particles of a certain size, losing their spiral velocity, will be caught by the fan draft and discharged from the mill. By moving the impact element toward the discharge end of the mill the distance fromthe point at which the whirling movement is generated to that at which the material impinges against the retarding cone 32 is diminished so that the particles which, under the first named conditions, would be discharged from the mill, are re- ,tained therein and the output is uniformly The whirling forces which tend tofiner. keep the material in the pulverizing cham: her will be greatest at the place where the impact element is located so that the nearer wardly along conical surface 32, that'is, to-

are used in the claims in a broad sense.

the impact element is placed to the retarding conethe finer the material will have to be before the fan draft can withdraw it from the chamber.

A new condition is brought about by the 7 adjustment of the impact element to the position indicated by the dotted lines in Fig. 1 in which the outer portions of the beaters revolve within cone 32. This adjustment is necessary only when the reduction of the material is to be carried to the extreme limit of fineness. With the impact element in this position the outer portions of the heaters set up a counter-movement of the material inward cone 31, which supplements the retardation 0f the outward movement of the material due, as above explained, to the gradually diminishing cross sectional area of this part of the chamber.

Figs. 4 and 5 show ,a further expedient for retarding the outward movement of the peripheral stratum- The regulator arms 33 revolve at a high speed and tend to create a counter-movement of the" material inwardly along conical surface 32 just as the impact element 18 creates such counterforce when adjusted to the position shown in Fig. 5. The inneig portions of the beater arms adjacent the hub 34 rotate at a lower velocity, naturally, than the extremities so that they form no appreciable obstruction to the discharge of the smaller particles through discharge opening 13.

By means of the arrangements above described, a pulverizing apparatus is provided which can be used on a great variety of difierent materials and to produce a pulverization varying very greatly in the degree of fineness of the product. As cone 31, or 31* as thecase may be, operates to forward the material through the mill, because of its flare toward the discharge opening, with the pulverizing element arranged close up to thefeed opening, the productof the mill will be relatively coarse, depending, of course, upon the character ofv the material operated upon. Onthe other hand, by the adjustment -of the impact element to the other extreme, and by the employment of the regulator, if necessary, the material operated upon may, if required, be reduced to such an extremely fine impalpable'powder that in issuing from the mill it will look like smoke.

The words cone and conical surfac? 15 may not be necessary that the converging surfaces conform strictly to the geometrical definition of a bone, although preferably this is the case.

I claim:

1. In pulverizing apparatus, the combination of a pulverizing chamber having a discharge opening and an interior conical surface convergent toward said opening, an

impact pulverizing elementin said. chamber which is revoluble 'upon and adjustable lengthwise of the axis of said conical surface, and means for producing adraft -of is revoluble upon and adjustable lengthwise of the axis of said conical surfaces, and means for producing a draft of air longitudinally through said chamber.

3. In pulverizing apparatus, the combination of a pulverizing chamber formed with a feed opening at one end and a discharge opening at the other, and with an interior conical surface which flares in the direction .of the discharge opening, an impact pulverizing element within the space bounded by said conical surface and substantially narrower than said space measured by its axis which is revoluble upon and adjustable lengthwise of the axis of said conical surface. and means for producing a draft of air longitudinally through said chamber in the direction of the'discharge opening:

4:. In pulverizing apparatus, the combination with apulverizingi chamber formed with annular bounding surfaces having a common axis and standing at an angle to each other, an impact pulverizing element revolubly arranged in said chamber and longitudinally adjustable on saidaxis, and means for producing a draft of air through said chamber.

5. In pulverizing apparatus, the combinationof a pulverizing chamber havingan interior conical surface, an impact pulverizing element therein which is revoluble upon-and adjustable lengthwise of the axis of said conical surface, means for producing a draft of air through said chamber longitudinally thereof, and means cotiperating with the pulverizing element for retarding theoutward movement of the material along the bounding suiface of the pulverizing chamber beyond the pulverizing element.

6. In pulverizing apparatus, the combination of a pulverizing chamber formed with a feed opening at one end and a discharge opening at the other and with interior, oppositely inclined conical surfaces, the one adjacent the feed opening tapering in the direction toward said opening, and the one adjacent the discharge opening tapering toward said opening, an impact pulverizing element in said chamber which is revoluble upon and adjustablelengthwise of the axis of said conical surfaces, means for producing a draft of air through said chamber from the feed end toward the discharge end,

and means for producing a counter-force in the material moving along the conical surface adjacent the discharge opening which; retards the .outward movement of the heavier particles thereof.

7. Inpulverizing apparatus, the combination of a pulverizing chamber formed with a feed opening at one end and a discharge opening at the other and with interior, oppositely inclined conical surfaces, the one adjacent the feed opening tapering in the direction toward said opening, and the one adjacent the discharge opening tapering toward said opening, an impact pulverizing element in said chamber which is revoluble upon and adjustable lengthwise of the axis of said conical surfaces, means@ for producing a draft of air through said chamber from the feed end toward the discharge end, and a regulator within the part of the pulverizing chamber adjacent the discharge opening comprising radial members revolving on said axis.

8. In pulverizing apparatus, the combination of a pulverizing chamber formed with a feed opening at one end and a discharge opening at the other and with interior, oppositely inclined conical surfaces, the one adjacent the feed opening tapering in the direction toward said opening and the one adjacent the discharge opening tapering toward said opening, an impact. pulverizing element in said chamber which is revoluble upon and adjustable lengthwise of the axis of said conical surfaces, and a regulator within'the part of the pulverizing chamber adjacent the discharge opening comprising radial members revoluble on and adjustable lengthwise of said axis. r

9. In pulverizing apparatus, the combination with a pulverizingchamber having a feed opening at one end and a discharge opening at the other and formed with in- (lorr ecti onein Letters at ntor1 32 1344;

I [sign] i I Ifi is hereby certified that in Letters Pebenj, flu-1,221,144, granted April 3, 1917,

dip oh the sp plicationiof -Joe Orites, of Chicago, I1lir 1ois, for an improvementin Pu lverizing Apparetl sj errers appear in the print ed specification requiring cor A rectienias follbwsz iEage 3, line 46, eiaim 5,- after the word means insert the W0rds coiipemting with the puilver'ising. element; sanie page and Claim, lines 48-49, strike eut the WOI dS wcoiiperating wii;h Elie pulverizing elementffl arid that the Y LefltersPatent should be read with these corrections therein that the same may eeriforfn to the record of film casein the'Patent Ofiice. I Sig ged andseeled this 1st da of May, A. 1)., 1917.

R. F. WHITEHEAD,

Acting Commissioher of Patents. 

